Desktop and personal computers, among other objects of value, have conventionally been a target for theft and robbery because, among other things, of their ready portability and the possibility that they can be resold. For this reason many identification systems which in some way indelibly identify the object when incorporated with it, showing that it is a stolen object and therefore making its resale difficult, have been conceived in the art.
For example, U.S. Pat. No. 2,225,520 discloses a stamp or seal especially designed to demonstrate that a fee has been paid, the authenticity of which can be verified by scraping off the upper layers of the seal, which exposes a mark or print authenticating the seal.
French patent FR 2,369,639 describes an anti-theft identification label which provides identification and/or recovery information printed onto the inner surface of the label using an ink which has greater affinity for the adhesive covering the surface than for its own plastic backing on which it is printed, such that any attempt to remove the label will result in at least some of the adhesive together with the information printed upon it remaining stuck on the object being protected.
Finally, European patent EP 0,465,305 discloses an identification plate showing identification information for the object on its top surface, and which also includes recovery information printed on its bottom surface, which if the plate is removed is transferred through adhesion to the wall of the object being protected, thus indicating that it is a stolen article.
All these identification plates in the prior art start from the basis that the weak point in the system is the adhesive joining the plate to the wall of the object requiring identification. However, present-day high-strength adhesives to a large extent make it difficult to tear off the plate, so that the weak point in the system is not the joint between the plate and the wall of the object requiring protection, but the upper layers of the plate, which are capable of being removed by abrasion, it then being possible to gain access to the printed information which might be erased, for example by abrasion, thereby neutralising the plate identification system.